Fair Values of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2013

Fair Value Disclosures [Abstract]

Carrying Values and Fair Values of Financial Instruments

The carrying values and fair values of financial instruments were as follows:

	June 30, 2013				December 31, 2012
	Carrying Value		Fair Value		Carrying Value		Fair Value
	(in millions)
Assets
Invested assets
Short term investments	$	2,002	$	2,002	$	2,528	$	2,528
Fixed maturities		37,300		37,300		38,076		38,076
Equity securities		1,845		1,845		1,663		1,663
Other invested assets		—		—		46		46
Liabilities
Long term debt		3,300		3,851		3,575		4,372

Fair Value of Financial Instruments Categorized Based Upon Lowest Level of Input

The fair value of financial instruments categorized based upon the lowest level of input that was significant to the fair value measurement was as follows:

	June 30, 2013
	Level 1		Level 2		Level 3		Total
	(in millions)
Assets
Short term investments	$	137	$	1,865	$	—	$	2,002
Fixed maturities
Tax exempt		—		19,142		5		19,147
Taxable
U.S. government and government agency and authority obligations		—		814		—		814
Corporate bonds		—		8,317		126		8,443
Foreign government and government agency obligations		—		7,052		10		7,062
Residential mortgage-backed securities		—		353		8		361
Commercial mortgage-backed securities		—		1,473		—		1,473
		—		18,009		144		18,153
Total fixed maturities		—		37,151		149		37,300
Equity securities		1,838		—		7		1,845
	$	1,975	$	39,016	$	156	$	41,147
Liabilities
Long term debt	$	—	$	3,851	$	—	$	3,851

	December 31, 2012
	Level 1		Level 2		Level 3		Total
	(in millions)
Assets
Short term investments	$	182	$	2,346	$	—	$	2,528
Fixed maturities
Tax exempt		—		19,907		6		19,913
Taxable
U.S. government and government agency and authority obligations		—		1,039		—		1,039
Corporate bonds		—		7,779		158		7,937
Foreign government and government agency obligations		—		7,008		—		7,008
Residential mortgage-backed securities		—		446		9		455
Commercial mortgage-backed securities		—		1,724		—		1,724
		—		17,996		167		18,163
Total fixed maturities		—		37,903		173		38,076
Equity securities		1,655		—		8		1,663
Other invested assets		—		—		46		46
	$	1,837	$	40,249	$	227	$	42,313
Liabilities
Long term debt	$	—	$	4,372	$	—	$	4,372